The present invention relates to an endoscopic instrument with cutting tool, having a shaft for introduction into duct-like body passages such as the rectum, trachea, or esophagus, and having an endoscopic optical system.
An instrument of this kind is known from the company brochure of Karl Storz GmbH & Co., Tuttlingen: "STORZ, THE WORLD OF ENDOSCOPY, PROCTOLOGY, FIFTH EDITION 1/92," 1992, page PRO 2. The instrument described there is a proctoscope.
A proctoscope is used in medicine for inspection of the anal duct and the lower portion of the rectum of a patient. For this purpose, the proctoscope is introduced into the anal duct with an obturator, inserted into a tube, whose distal end is of beveled configuration. The obturator is then pulled back out of the tube, and instead an insert with lateral windows is introduced into the tube; with this, the anal duct can be inspected via an endoscopic optical system in order to detect proctological diseases.
If a tumor in the intestinal wall is detected during the proctological examination, it must then be surgically removed. For surgical removal of deep tumors in the lower rectum, it is necessary to introduce a circular incision into the intestinal wall in the circumferential direction. This operation is very difficult and time-consuming and cannot be performed with the conventional proctoscope alone, instead requiring a special surgical incision instrument.
The invention is not limited, however, to a proctoscope of this kind. Further comparable endoscopic instruments that are introduced into duct-like body passages in order to inspect the body passage are the rectoscope, esophagoscope, and tracheoscope. Rectoscopes are also introduced into the bowel in order to inspect the bowel. An esophagoscope is used to inspect the esophagus, and a tracheoscope to inspect the bronchial tubes. In the case of these endoscopic instruments as well, the only ones available at present are those with which the corresponding body passages can be inspected, but with which it is not possible to introduce a circular incision into the wall of the respective body passage.
DE-A-27 37 014 discloses an endoscope for slitting through urethra constrictions. The endoscope has a shaft tube in which a knife for slitting through the constriction is provided distally. The knife can be pivoted out about a transverse axis through a longitudinal slot in the shaft by way of a longitudinally displaceable wedge arranged distally from it, using a proximal handle via a wire pull, from a rest position in which the knife lies recessed in the shaft. The knife is used to make an incision in the longitudinal direction of the shaft axis.
Also known from U.S. Pat. No. 4,674,500 is a surgical incision instrument that is used in arthroscopy and in those surgical procedures in which access to the surgical site is limited or difficult. This instrument accordingly has a very thin shaft, bent over laterally at the distal end, in which a knife blade is received displaceably in the longitudinal direction of the shaft. The knife is of bendable configuration, so that by being advanced, it can be pushed out of the laterally curved distal end of the thin shaft in order to make an incision. This instrument with a curved shaft is not suitable, however, for use in a duct-like body passage.
It is therefore the object of the invention to improve an endoscopic instrument of the kind cited initially in such a way that it is possible with the instrument not only to perform an inspection of the respective body passage, but also to surgically remove a tumor by introducing an incision into the wall of the body passage.